Re: [PATCH 3/3] media: uvcvideo: eUSB2 double isochronous bandwidth support

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Mathias,

Thank you for the patch.

On Mon, Jun 16, 2025 at 12:37:30PM +0300, Mathias Nyman wrote:
> From: Tao Q Tao <tao.q.tao@intel.com>
> 
> Add eUSB2 support to check total number of bytes, isochronous endpoint
> will transfer every service interval(SI).
> 
> Co-developed-by: Amardeep Rai <amardeep.rai@intel.com>
> Signed-off-by: Amardeep Rai <amardeep.rai@intel.com>
> Signed-off-by: Tao Q Tao <tao.q.tao@intel.com>
> Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
> ---
>  drivers/media/usb/uvc/uvc_video.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
> index e3567aeb0007..a888f84208c6 100644
> --- a/drivers/media/usb/uvc/uvc_video.c
> +++ b/drivers/media/usb/uvc/uvc_video.c
> @@ -1906,6 +1906,11 @@ u16 uvc_endpoint_max_bpi(struct usb_device *dev, struct usb_host_endpoint *ep)
>  	case USB_SPEED_SUPER:
>  	case USB_SPEED_SUPER_PLUS:
>  		return le16_to_cpu(ep->ss_ep_comp.wBytesPerInterval);
> +	case USB_SPEED_HIGH:
> +		psize = usb_endpoint_maxp(&ep->desc);
> +		if (psize == 0 && le16_to_cpu(dev->descriptor.bcdUSB) == 0x220)
> +			return le32_to_cpu(ep->eusb2_isoc_ep_comp.dwBytesPerInterval);
> +		fallthrough;

Instead of adding yet another case here, and eventually in a bunch of
other drivers, could we centralize retrieval of the maximum bpi value in
a helper function provided by the USB core ?

>  	default:
>  		psize = usb_endpoint_maxp(&ep->desc);
>  		psize *= usb_endpoint_maxp_mult(&ep->desc);

-- 
Regards,

Laurent Pinchart